A hollow fiber membrane module having a hollow fiber membrane as a separation membrane is used for various applications including filtration of liquid or gas, solid/liquid separation, concentration of a substance, removal or concentration of cellular bodies, and removal of gas dissolved in liquid (that is, deaeration).
The hollow fiber membrane module is produced by encasing a hollow fiber membrane bundle in a module case, injecting a potting material to an end part of the hollow fiber membrane bundle followed by curing to form a potting part, and cutting an end part of the potting part together with the hollow fiber membrane bundle so as to open the end part of the hollow fiber membrane bundle. The injected potting material is evenly distributed either between hollow fiber membranes or between a hollow fiber membrane bundle and an inner peripheral surface of a module case, and according to curing of the potting material, the hollow fiber membrane bundle is fixed in the module case.
At the time of using a hollow fiber membrane module, the potting part is brought into contact with a liquid to be treated of a membrane treatment subject or a treatment liquid after membrane treatment. For such reasons, the potting material is required to form a potting part which exhibits excellent chemical resistance to those liquids. If the potting part exhibits poor chemical resistance, in accordance with use of a hollow fiber membrane module, a liquid to be treated of a membrane treatment subject or a treatment liquid after membrane treatment permeates the potting part to cause swelling or the potting part is dissolved out by those liquids. As a result, the potting part may peel off from a hollow fiber membrane or from an inner peripheral surface of a module case, or disintegration of the potting part occurs. Accordingly, a leak is yielded. Furthermore, when the potting part is dissolved into a treatment liquid, composition and properties of the treatment liquid are also affected.
Under the circumstances described above, a potting material capable of forming a potting part which exhibits a little change in mass between before and after immersion in a chemical liquid and has excellent chemical resistance is disclosed (Patent Literature 1 and the like)
Furthermore, a gas separation membrane module for separating organic vapor which has durability of sufficiently maintaining air tightness between an inner space and an outer surface of a hollow fiber membrane even when being used in organic vapor at high temperature and high pressure is disclosed (Patent Literature 2 and the like).